Balanced control surface of aircraft



Nov. 17, 1925- 1,561,619

. H. SMITH BALANCED CONTROL SURFACE OF AIRCRAFT Filed April 10, 1925 7/ WW I, W

' aswa" FNVEON TOR.

less Patented Nov. 17, 1925. I

UNITED STATES HERBERT SMITH, OF KINGSTON HILL, ENGLAND.

BALANCED CONTROL SURFACE OF AIRCRAFT.

Application filed April 10, 1925. Serial No.'22,083.

To all whom it may concern:

Be it known that I, HERBERT SMrrH, a

subject of the King of Great Britain, residing at The Pines, Kingston Hill, in the county of Surrey, England, have invented Improvements in and Relating to Balanced ControL Surfaces of Aircraft, of

which the following is a specification.

This invention relates to improvements in balanced control surfaces or ailerons of the wing aerofoils of air craft. In such ailerons as at present constructed, not only is appreciable effort required to operate them but there is a tendency after a certain limited opening movement for the aeroplane to snatch or to become diflicult to control, and the primary objects of the present invention are to overcomethis drawback and to reduce to any desired degree the amount of effort required to operate smoothly the lateral controls of aeroplanes.

The present invention comprises essentially so shaping and pivoting the ailerons of wing aerofoils that in opening together they produce a couple tending to turn the aeroplane laterally and. at the same time assist the effort required to smoothly operate them.

This invention will be now more particularly described making reference to the accompanying drawing in which Fi 1 is a broken view in plan--more or iagrammatic-of a biplane embodying the present invention.

line --A of Fig. 1.

Fig. 3 is a similar View on line BB of i v Fig. 1.

Fig. 4 is a similar view to Fig. of a monoplane embodying the present invention.

Fig. 5 is an enlarged sectional view on either of the lines CG of Fig. 4, and

Fig. 6 is a similar view on either of the lines D-D of Fig. 4.

Throughout the views similar parts are marked with like letters ofreference.

Referring more particularly to Figs. 1-3, the 'aerofoils m, m are of the usual cambered section and so arranged that the camber a of the ailerons a of the upper wing aerofoils a: is on the upper surface and the camber a of the ailerons a of the lower wing aerofoils w is on the lower surface These ailerons a a are each pivoted or hinged at t to the aerofoils :0, m and the position of practical clearance Fi 2 is an enlarged sectional view on such hinging or pivoting point being so chosen as togovern the amount of effort required to operate them. The leading edge of each aileron a (11 makes the smallest with the aerofoil to which the aileron is hinged.

The ailerons a a of the starboard (Fig. 3) and port (Fig. 2) sections of the wing aerofoils w, m are so connected as to open together so that as the ailerons of the port sections of the aerofoils open in one direction those of the starboard sections of the aerofoils open in an opposite direction and owing to the shape: and arrangement of the hinging point of each aileron, the leading edge of both the ailerons a of the lower section of the starboard aerofoil and the upper section of the port aerofoil will open together in opposite directions, say for instance upwardly and downwardly respectively, as shown in dotted lines, whilst the leading edges of the ailerons m of the upper and lower sections of the starboard and port aerofoils respectively will be masked, within limits, by their wing sections, as shown.

In applying the present invention to monoplanes, the aileron, on the one side has the camber on aportion of its upper surface and the remaining portion is'cambered on the lower surface and the aileron on the other side is similarly shaped but the portions of the said surface are oppositely arranged. A convenient arrangement for instance is that shown'in Figs. 46 in which the aileron of the starboard side (see the right hand side of Fi 4) of the aerofoil a:

is formed so that the first portion a of its leading edge and surface is cambered on its upper surface, the next or middle portion a or approximately half of the total leading edge and surface is cambered on its lower surface and the remaining portion a of its leading edge and surfaceis cambered on its upper surface. The aileron on the port side (the left hand side of Fig. 4) of the aerofoil a: will then be cambered in an alternate manner, i. e. the first portion a of its leading edge and surface is' cambered on its lower surface, the next portion a or approximately half of the total leading edge and surface iscambered on its upper surface and the remainig portion a of its leading edge and surface is cambered on its lower surface, as shown.

It willhe understood that both ailerons a* are coupled together and pivoted or hinged at b to the aerofoil m and the position of such hinging or pivoting point is so chosen as to govern the amount of efiort required to operate them. The leading edge of each aileron makes the smallest practical clearance with. the aerofoil.

By such arrangement the amount of effort to operate smoothly the lateral controls of air craft may be reduced to any desired degree.

I declare that what I claim and desire to secure by Letters Patent is 1. In an aeroplane, forming the opposed ailerons of the wing aerofoil with oppositely arranged cambers so that one aileron wili open downwards and the other aileron will open upwards so that a gap is made by some portion of both cambers immediately the ailerons are moved whereby both assistance is given to open and the air resistance is balanced, as set forth.

2. In an aeroplane, forming the ailerons on the one side'of the wing aerofoil with a camber on a portion of its upper surface and the remaining portion with a camber on its lower surface, forming the aileron on the other side with similarly shaped surfaces but oppositely arranged, hinging said ailerons to the aerofoil and so connecting them that they move together, as set forth.

HERBERT SMITH. 

